Well, our week was a bit caddy-whampus, and the Cashew Chicken was made on the scheduled day, but it did get made. Points for that right?
I even remembered to take pictures as I was making it!
You know your own family size, so you can adjust portions accordingly.
I used 1 kg of chicken cut into small pieces and about 4 cups of chopped vegetables. You can use whatever veggies you like, we tend to have onions, peppers (sweet), carrots and broccoli.
First, gather your sauces and such.

You will need: dried red chilies, Thai chili paste, oyster sauce, some soup flavoring ( envelope) and good soy sauce. The brand pictured is called Golden Mountain sauce. I believe all these things can be found at most any Asian market and many grocery stores now.
Before cooking, chop chicken, vegetables and mince garlic, about 3-4 cloves.
Heat a couple of TBL oil in a wok or large skillet over fairly high heat.
One of the keys to Thai cooking, is using high heat for a short time to cook the food quickly.

Stir fry the garlic until it just begins to turn brown, then add the chopped chicken.
To the chicken and garlice add chili paste.

There is room here for some fiddling. I found that for our family, we like the taste of this dish more as I added more chili paste. I use nearly 1/2 the jar at a time. This chili paste is really not all that spicy, just flavorful, although you may want to begin by adding less for the first time and increase it as your family tolerates.

Stir and cook the chicken in the chili paste until cooked through.
Add a small handful of the dried red chilies. This is what will add the most heat, so if you like it hotter, add more.

Add your oyster sauce. I have not measured this, but you can see the size puddle on the utensil. 
Try somewhere around 2 TBL
Stir in a bit a bit of water, approx 1/4 to 1/2 cup and sprinkle some soup base/seasoning in. Stir to mix. If you cannot get powdered soup base, just crush up a boullion cube and add it. You should have cooked chicken in a reddish gravy at this point.
Keeping the heat high, stir fry the veggies for just a minute or two. You do not want them to be overly soft and mushy. They should still be slightly crisp.
(at this point you can also add your cashews and cook them in at this point, but some kids in our family do not like them and so we add them on top. No sense wasting perfectly good cashews on fussy children.)

Serve with rice, of course and enjoy. Aroy!

Here is a close up of the brand chili paste I use, the best one we have found. I know it is available in the US, but cannot say for elsewhere.
Happy cooking!
P. S. If you like to stir fry often, I love the spatula-type tool that I used in these pictures. I highly suggest looking at a cooking store or asian market for one. It is wonderful, and I have fewer spills using it than I did when I just used a large spoon or metal spatula. In Thai it is called a daa-lii-oo, if that helps.